1. Field of the Invention
The present invention relates to a magnetic recording/reproducing apparatus which is able to record and reproduce a signal from an image sensor such as a CCD, as well as a composite video signal, in particular, to the magnetic recording/reproducing apparatus equipped with such the image sensor formed or constructed as an unit, in which a camera portion and a video signal processing portion thereof are realized by digital signal processing circuits.
2. Description of Related Art
Almost of video signal processing in a conventional VTR set of stationary type for home use and a portable VTR equipped with a camera formed or constructed as an unit, such as so-called a camcorder, is constructed with a signal processing circuit for an analogue signal processing. However, with a VTR under the S-VHS standard and/or a camcorder under the Hi8 standard which are already available on the market, the signal processing circuit thereof is constructed with a digital signal processing circuit.
Especially, for the case of the camcorder, a system is proposed, in which an A/D converter is commonly used by sharing with a digital processor of the camera portion (hereinafter, "a camera DSP") and a digital processor of the VTR portion (hereinafter, "a video DSP") thereof, for example in Japanese Patent Laying Open No. 8-51565 (1996). In this case, for decreasing the number of pins of the IC of the A/D converter, three kinds of input signals, i.e., a camera signal from the camera system, a video signal from a line input terminal, and a reproduced video signal from a VTR system, are inputted to the A/D converter for common use after being selected through a change-over switch, and a digital signal outputted therefrom is distributed through another change-over switch. Further, an interface circuit is provided for compensating level differences occurred during this period among those three kinds of signals.